The present invention relates to a plate inserting device for inserting the distal end bent portion of a new plate into the groove portion of a plate cylinder.
As shown in U.S. Pat. No. 6,393,986 a conventional plate inserting device comprises a plate cylinder on which a plate is to be mounted and a plate-inserting press roller which is pivotally supported to be able to be thrown on/off with respect to the outer surface of the plate cylinder. When inserting a plate, the plate cylinder is rotated with the press roller being in contact with the outer surface of the plate cylinder. Then, the press roller abuts against the distal end bent portion of the new plate to be supplied to the plate cylinder so as to insert the distal end bent portion of the new plate into the groove portion of the plate cylinder.
In the conventional plate inserting device described above, as the press roller is supported rotatably, it rotates when inserting the distal end bent portion of the new plate into the groove portion of the plate cylinder. Hence, as shown in FIG. 9A, a distal end bent portion 5a of a new plate 5 does not come into tight contact with an inclined surface 32a of an elongated groove 32 of a plate cylinder 6 but is spaced apart from it due to its own weight. This state becomes typical as the new plate 5 becomes bulky and its weight increases. When the distal end bent portion 5a of the new plate 5 is spaced apart from the inclined surface 32a, even when a winding rod 33 is pivoted to clamp the distal end bent portion 5a, the suspended state of the distal end bent portion 5a cannot be eliminated. Consequently, the new plate 5 may be erroneously mounted in a shifted state by being twisted at its leading edge and trailing edge in the widthwise direction of the plate, as indicated by an alternate long and two short dashed line in FIG. 9B.